Severe Thunderstorm Warning 11, NWS Las Vegas, NV

Area Forecast Discussion
National Weather Service Las Vegas NV
706 PM PDT Mon Jun 2 2025

.SYNOPSIS...Additional rounds of showers and thunderstorms are
possible through midweek as sufficient moisture and instability
remain in the area. Precipitation totals should be light and most
activity will take place over high terrain. The area slowly dries
out and temperatures begin to climb as a ridge builds later this
week.

&&

.UPDATE...

Early this evening, storms have largely dissipated over the
Sierra, with focus remaining on a cluster of strong to severe
thunderstorms currently moving out of southern Lincoln County into
northern Clark County. The strongest storm is a cell that's been
rather persistent, and capable of producing large hail and
damaging wind gusts as it travels southward down Highway 93 toward
Interstate 15. Notably, this storm is also producing rainfall
rates in excess of 3 inches per hour. The longevity of this storm
remains in question, but overall, storms are expected to
gradually weaken after sunset with the loss of insolation.
However, some convective persistence can be expected along
outflow boundaries as these boundaries sag southward across Clark
and Mohave Counties into tonight, given shear has ticked up the
past few hours to 25-30KT across Clark County and through the
Lower Colorado River Valley, and CAPE remains between 1000-1500
J/kg. Hazards with storms will be frequent lightning, heavy rain,
and gusty winds, along with reduced visibility in rain or blowing
dust, though hail cannot be ruled out, especially early this
evening. DCAPE remains around 1000-1250 J/kg as well, lending
additional credence to the wind threat this evening. Have made
some adjustments to PoPs, sky, and weather to account for current
observations and expected trends, with the remainder of the
forecast on track this evening.

&&

.DISCUSSION...

The upper low that helped draw in tropical moisture has shifted off
to the east leaving behind plenty of low level moisture. Dew points
across the region are currently in the 40s and 50s, which is very
unusual for June. So far today, showers and thunderstorms have been
firing along the Sierra and White Mountains of Inyo County and
across portions of northern Lincoln and central Nye counties. These
areas are currently seeing the greatest instability with CAPE values
in the 500-1000 j/kg along with LIs ranging from 0/-2 deg C. Storms
over the Sierra and White Mountains will gradually decrease this
evening with loss of daytime heating, but the storms over Lincoln
County have the potential of maintaining and expanding this
afternoon and evening as they move south. Those storms will be
moving into areas that are seeing increasing instability as the
earlier cloud cover continues to erode. Along with the increasing
instability, high dew points and high PWs will lead to some storms
producing brief heavy rain and minor flooding concerns. We did get a
spotter report of small hail near Eagle Valley in Lincoln County as
the storm went overhead. While most of the thunderstorm activity is
expected to remain in Utah, areas of southern Lincoln, northeast
Clark, and northern Mohave counties could see some stronger storms as
we go through the afternoon and into the evening. We could also see
some gusty outflow winds as DCAPEs in the area are around 1000 j/kg
and it is possible that some of those winds could make it into the
Las Vegas Valley. Storms will gradually diminish late tonight.

Storms Tuesday are expected to be more favored over the southern
half of the CWA as deep moisture remains in place. PWs will still be
around 200-300 percent of normal which translates to around 1.00" -
1.50" inches. With plenty of morning sunshine this should translate
to scattered showers and thunderstorms in the afternoon as
conditions will remain rather unstable. Most of these storms will
favor the higher terrain, but some valley locations could see a
storm or two. Flash flooding could be more of a concern as winds
aloft remain around 10 kts or less.

On Wednesday, another low off the southern California coast will
begin to shift inland. This low will take a very similar path to the
previous low and although there isn't a significant amount of
tropical moisture available, the latest models indicate increasing
PWs and surface dew points once again. This will lead to more
scattered showers and thunderstorms over the southern half of the
CWA. Again, these will likely be favored over the higher terrain,
but any storms could produce heavy rain. WPC has added our eastern
counties, including Lincoln, Clark, and Mohave into a marginal
Excessive Rain Outlook.

.LONG TERM...Thursday through Monday.

Weak northwest flow will continue across the region late in the
week.  A series of weak short waves will move through the flow and
interact with lingering moisture, resulting in slight PoPs through
early Friday.  The best chances will be over the southern Great
Basin and Arizona Strip.  The remaining moisture should move east of
the area by Friday afternoon, bringing an end to the precipitation
chances. Despite the shortwaves, a high-pressure ridge building over
the eastern Pacific and northern Mexico will result in increased 500
mb heights across the Desert Southwest. As such, temperatures will
climb back to 4 to 8 degrees above seasonal norms heading into the
weekend, and temperatures approaching 10 degrees above normal
heading into next week. This will result in desert valleys
experiencing high temperatures in the 100s once again, and
widespread "Moderate" Heat Risk from Sunday onward.

&&

.AVIATION...For Harry Reid...For the 00Z Forecast
Package...Scattered convection will continue through north and
northeast corridors through the evening. A few showers may get into
northeast Clark County between 03Z-06Z, but precipitation is not
expected in the valley this evening. After a lull in activity
tonight, scattered convection is expected to develop Tuesday
afternoon across southern Nevada into San Bernardino and Mohave
counties. There is a chance that showers and thunderstorms will move
into the valley terminals Tuesday after 21Z which could bring
moderate to heavy rain, CIGs below 10kft, lightning, and sudden
gusty winds over 30KT.

Most likely, winds will remain un-impactful through tonight as east
winds transition to the south or southeast this evening. Wind speeds
of 8-10KT are possible through tonight before becoming light early
Tuesday morning. Still watching the potential for northeast winds to
push through the valley between 04Z-06Z tonight. Confidence remains
low for this to occur, but it it did occur, expect gusty northeast
winds over 25KT. After a period of light winds Tuesday morning, east
to southeast winds will return Tuesday afternoon and will remain
light. This is outside eof the potential for erratic outflow winds,
which would be possible with thunderstorms after 21Z. Low confidence
in the wind forecast after 00Z Tuesday evening due to convective
influence and what sets up in the afternoon.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 00Z Forecast Package... SCattered convection
will continue through the afternoon in the Southern Great Basin into
the terrain of Inyo County. Most likely, thunderstorms will diminish
after sunset, however the potential exists for ongoing precipitation
in southwest Utah and Lincoln County to merge and move through
northeast Clark into northern Mohave County through 08Z tonight.
With any thunderstorms this evening and tonight- lightning, sudden
gusty winds, moderate to heavy rain, and CIGs to 8000ft would be
possible. KBIH has the highest risk of thunderstorm impacts through
about 04Z. After a dry period late tonight through Tuesday morning,
another round of scattered convection will develop along and south
of the I-15 as well as in the Sierra. Similar thunderstorm impacts
would be possible on Tuesday to today, though coverage may be more
widespread than today. The only TAF site that should not have a
threat for thunderstorms Tuesday afternoon is KEED and KIFP as
convection should not make it into the Colorado River Valley until
after 00Z. Outside of convection, south to southwest winds around 10
KT this evening will diminish after sunset. Light winds return
tonight before similar winds return late Tuesday morning and
afternoon. Additional convection may develop Tuesday afternoon along
and south of the I-15 as well as in the Sierra.

&&

.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.

&&

UPDATE...Phillipson
SHORT TERM...Gorelow
LONG TERM...Planz
AVIATION...Nickerson

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